Am. J. Trop. Med. Hyg., 73(1), 2005, pp. 125-130
Copyright © 2005 by The American Society of Tropical Medicine and Hygiene
GENETIC POLYMORPHISMS OF EOSINOPHIL-DERIVED NEUROTOXIN AND EOSINOPHIL CATIONIC PROTEIN IN TROPICAL PULMONARY EOSINOPHILIA
YAE-JEAN KIM*,
V. KUMARASWAMI,
EUNHWA CHOI,
JIANBING MU,
DEAN A. FOLLMANN,
PETER ZIMMERMAN, AND
THOMAS B. NUTMAN
Helminth Immunology Section, Laboratory of Parasitic Diseases, Laboratory of Malaria and Vector Research, and Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland; Tuberculosis Research Centre, Chennai, India; Department of Pediatrics, Seoul National University College of Medicine, Seoul, South Korea; Division of Geographic Medicine, Department of Medicine, Case Western Reserve University, University Hospitals of Cleveland, School of Medicine, Cleveland, Ohio
 |
ABSTRACT
|
Because eosinophil-derived neurotoxin (EDN) and eosinophil cationic protein (ECP) are critical in the pathogenesis of tropical pulmonary eosinophilia (TPE), we analyzed genetic polymorphisms of both in 181 individuals from southern India with varying clinical manifestations of Wuchereria bancrofti infection (including 26 with TPE). Using haplotype frequency analysis, we identified four known (of nine) and two novel haplotypes for EDN (1, 2, 7, 8, 10, and 11). For ECP, five (of seven known) haplotypes (15) were identified. Although we found no significant association between frequencies of EDN and ECP polymorphisms and TPE development, we observed a unique pattern of EDN and ECP polymorphism distribution among this population. Genotype TT at locus 1088 of ECP in one TPE patient was not observed in any other clinical group. Although the EDN and ECP polymorphisms appear unlikely to be associated with the development of TPE, further analyses will be more definitive.
 |
INTRODUCTION
|
Tropical pulmonary eosinophilia (TPE), an unusual manifestation of human lymphatic filarial infection, is characterized by eosinophilic pulmonary inflammatory infiltrates and marked elevations of serum IgE and circulating eosinophils, all believed to be mediated by immunologic hyperreactivity to filarial parasites or their antigens. Although 129 million people worldwide are infected with lymphatic filariasis, fewer than 0.01% develop TPE.1 It is unclear what factors predispose patients to this rare, localized, and profound immunologically dysregulated state, but the findings of association between chitotriosidase 1 (CHIT1) and mannose-binding lectin 2 (MBL2) and susceptibility to human filarial infection have implicated underlying host genetics as partially playing a role.2
Typically, microfilariae circulate in the blood of patients with lymphatic filariasis without significant clinical consequences. In the case of TPE, however, these microfilariae appear to be trapped in the lung on their first pass through the circulation, where they are presumed to initiate an inflammatory response. In contrast to the majority of people with lymphatic filariasis who have a down-regulated T cell response to the parasites, patients with TPE mount a robust systemic and localized immune response3 that includes elevations of both polyclonal and filaria-specific-IgE and IgG4 as well as expansion of interleukin-4 (IL-4) and IL-5-producing T cells.5
Eosinophils are the predominant effector cells seen in the lungs of patients with TPE, and unlike the rare eosinophils in the bronchoalveolar lavage fluid of normal lungs, the pulmonary eosinophils in TPE are degranulated and activated.6 Moreover, a recent study has demonstrated that the localized release of the eosinophil degranulation products eosinophil-derived neurotoxin (EDN) and eosinophil cationic protein (ECP) are critical in mediating some of the pathology seen in TPE.7
The EDN and ECP genes are closely linked on chromosome 14q24-q31,8 and their protein products can be found in the large specific granules of eosinophils.911 They both are members of the eosinophil-associated ribonuclease family. EDN (RNase 2) has antiviral activities against both respiratory syncytial virus and human immunodeficiency virus (HIV) in vitro.12,13 ECP (RNase 3) has cytotoxic activity14 and, by itself, can kill microorganisms including bacteria, protozoa, and helminths in vitro.1517 In addition, ECP can regulate fibroblast activity, modulate airway mucus secretion, and interact with the coagulation and complement system.18 Sequence variations in both EDN and ECP have been identified. For EDN, nine polymorphic sites leading to nine haplotypes were defined, whereas for ECP, seven polymorphic sites leading to eight haplotypes have been observed.19 Another polymorphism in ECP has recently been shown to be associated with allergic symptoms.20,21
With this as a backdrop, we hypothesized that genetic polymorphisms in EDN and ECP might play an important role for the development of TPE. In the present study, we have screened for the polymorphisms of EDN and ECP in a south Indian population and have observed different distribution patterns of haplotypes in this population from those of other groups reported previously.19 We have also found two novel haplotypes (haplotypes 10 and 11) for EDN. Moreover, we have observed homozygosity of a T allele at locus 1088 for ECP that results in a haplotype seen only in a patient with TPE.
 |
MATERIALS AND METHODS
|
Participants.
The study was performed using protocols reviewed and approved by the National Institute of Allergy and Infectious Diseases Institutional Review Board (IRB) and the IRB of the Tuberculosis Research Centre, Chennai, India. Informed consent was obtained from each study participant. Our study population consisted of 181 individuals from south India: 58 normal (N), 55 with asymptomatic microfilaria positive (AMF), 42 with chronic lymphatic dysfunction/elephantiasis (CP), and 26 with TPE. For three EDN samples in the N group and one ECP sample in the CP group, a polymerase chain reaction (PCR) product could not be obtained; therefore, analysis of these samples was not performed.
Polymorphism analysis.
Genomic DNA was obtained from peripheral blood by conventional methods.22 The EDN and ECP genes were amplified by a PCR with primer sets EDN 1f (5'-TCCAGAGTTTGGATCTAACCA-3') and EDN 4r (5'-TAA TGAAGACACACAGAGACTTT-3') and ECP 1f (5'-CCCAGAGTCCAGATCCCACCG-3') and ECP 4r (5'-GTCACTAAATGACAGCAG AGG-3'),19 respectively, derived from the published human sequences (GenBank accession numbers X55987 and X16545). High-fidelity Taq polymerase (Life Technologies, Rockville, MD) was used. The PCR products were purified by ExoSAP-IT (United States Biochemicals Corp., Cleveland, OH); 5 µL of the treated product was used in a sequencing reaction with Big-Dye terminator chemistry on an ABI3100 DNA sequencer (Applied Biosystems, Foster City, CA). All known and potential polymorphic sites and discrepancies were verified by visual inspection.
Haplotype predictions and reconstructions were determined by using PHASE 1.0 (Isis Innovation Ltd., Summer-town, Oxford, United Kingdom).23 Sequence data were combined with clinical information for statistical analyses in comparisons between N and the three infected groups (AMF, CP, and TPE) and between TPE and the other two infected groups (AMF and CP).
Statistical analysis.
Differences in genotypic distributions were tested by contingency table analysis using Fishers exact test with SPSS version 11.5 (SPSS Inc., Chicago, IL). For haplotype frequency analysis to test equality of the distribution of haplotypes across patient groups, a Monte Carlo analysis was used.24 A random contingency table of haplotype pairs by patient groups was generated with the same column and row sum totals as the actual data; this table was then transformed to a contingency table of unique haplotypes cross-classified by patient group. Chi square was calculated for this reduced table. This procedure was repeated 1,000 times, and the 1,000 simulated chi-square statistics provide a reference distribution for the chi-square statistics of the original data.
 |
RESULTS
|
Identification and confirmation of EDN and ECP polymorphisms.
Among nine observed haplotypes and one hypothetically predicted haplotype for EDN and eight known haplo-types for ECP, we identified six haplotypes (1, 2, 7, 8, and two novel haplotypes) for EDN and five haplotypes (haplotypes 15) for ECP (Table 1
). For EDN, four polymorphic sites among nine known sites were observed (Table 2
). Among them, one synonymous site in a coding region and three sites in noncoding regions were observed (Table 3
). All the sites were biallelic. For ECP, four polymorphic sites among seven known sites were observed (Table 2
). Among them, one non-synonymous site in the coding region and three sites in the noncoding region were identified (Table 3
). All these sites were biallelic. The results of haplotype frequency analysis in normal individuals in our study were compared with those of an Asian group studied previously that had compared frequencies among different groups19 (Table 1
). In the present study, for EDN, haplotypes 1, 2, and 7 were seen most commonly among the south Indian normal population in frequencies that were moderately different than previously reported in a different Asian population. We observed EDN haplotypes 1, 2, 7, and 8, with haplotype 1 being the most common haplotype (70.9%). Of note, we did not find haplotypes 3, 4, 5, 6, and 9, which is not surprising since haplotype 5 has been reported to be restricted to Caucasians and haplotypes 3, 4, 6, and 9 restricted to African-Americans.19 Haplotype 8 was observed in one participant. Of interest, two novel haplotypes, 10 and 11, were observed in the CP group (Table 1
). Haplotype 10 was predicted (but not observed) in a previous study,19 and another novel haplotype has tentatively been given the name haplotype 11. For ECP, we observed four haplotypes (1, 2, 3, and 4) in the normal south Indian group, with haplotype 2 being the most common (40.5%). The frequencies of the haplotypes again differed from those seen previously among Asians.19 Moreover, we did not observe haplotypes 6, 7, and 8, which have been reported to be restricted to African-Americans, or haplotype 5, also previously found predominantly in African-Americans.19
Analysis and distribution of genotypes.
Genotype frequency analysis of EDN showed no significant differences in the genotype distribution for all observed polymorphic sites in the EDN gene among the four clinically different groups (N, AMF, CP, and TPE) or between the N group and the three infected (susceptible) groups (AMF, CP, and TPE). There was also no difference between the TPE group and the other two infected groups (AMF and CP) (Table 2
). We did not observe polymorphisms at site 1011, a site implicated in the ribonuclease function of EDN. It is known that among the three polymorphic sites (836, 980, and 1011) within the protein-coding sequence, two synonymous polymorphic sites (836 and 980), and one nonsynonymous polymorphic site (1011, in which a C/A mutation results in a His/Asn in at one of the three amino acid residues that form the catalytic site of the RNase) cause EDN to become nonfunctional.
Genotype frequency analysis of ECP showed no significant differences in genotype distribution for all observed loci among the four groups, between the N group and the three infected (susceptible) groups (AMF, CP, and TPE), or between the TPE group and the other two infected groups (AMF and CP) (Table 2
). Of interest, one TPE patient was homozygous for T (compared with A) at this locus, while none of the others studied was homozygous.
Haplotype frequency analysis.
Polymorphisms in the EDN gene showed no significant differences in frequencies among the four groups studied, between the N group and the three infected groups (AMF, CP, and TPE), or between the TPE group and the other two infected groups (AMF and CP). Among the nine known haplotypes and one predicted haplotype for EDN, we identified six haplotypes (1, 2, 7, 8, 10, and tentatively 11) (Table 4
). Haplotype 1 was the most common haplotype in all groups. Among the eight known ECP haplotypes, five were found in the south Indian population. Haplotype 5 was observed only in one TPE patient (Table 4
). This TPE patient was homozygous for a T allele at position 1088; however, there was no obvious difference between this patient and other TPE patients in terms of male gender, high-grade eosinophilia, and abnormal pulmonary function test results.
Sample size analysis.
Because the ability to determine statistical significance is directly related to the number of participants, simple calculations were performed to assess how the P value would be changed if the sample sizes were doubled and the observed proportions remained the same. In Table 2
with EDN = 416, the P value changed from 0.40 to 0.23. In Table 4
with haplotype EDN, the simulated P value changed from 0.79 to 0.38, while for haplotype ECP, the P value changed from 0.14 to 0.02. To definitively identify modest differences in proportions of the kind seen in this paper would require a larger study.
 |
DISCUSSION
|
We have explored the role polymorphisms of EDN and ECP might play in the development of TPE. Although we were unable to find any statistically significant relationship in the distribution of genotypes, alleles, and haplotypes for the development of TPE, it is of particular note that we observed haplotype 5 only in a TPE patient, while we did not detect this haplotype in any other group. We also observed two new haplotypes of EDN, 10 and 11, in the CP group. Moreover, we have defined the distribution of haplotype frequencies in this south Indian population, showing it to be different from that of an Asian population in a previous report.19
Some evidence suggests that TPE has an underlying genetic basis. It has a minuscule incidence rate1,25,26 and biases for male gender1,26 and geography (mostly found in India, Brazil, and southeast Asia).1,6,25,26 Moreover, data from Brazil27 and south India (Gopinath R and others, unpublished data) have identified cases that have occurred among siblings.
In lymphatic filariasis, it has been reported that there are associations between the HH genotype of CHIT1 and the XX genotype of the promotor region in MBL2 and susceptibility to lymphatic filarial infection2 in this same population, but not with the development of TPE. This finding, however, appears to be population specific in that these same polymorphisms were not associated with disease susceptibility in Papua New Guinea.28 In a related filarial disease, onchocerciasis, it has been observed that there was an association between HLA-DQ alleles and the level of immune response to parasite antigens,2931 and the IL-13 variant Arg110Gln has been shown to be significantly associated with an immunologically hyper-reactive form of onchocerciasis, sowda,32 a condition often believed to parallel TPE from an immunologic standpoint.
It is well known that TPE patients have extreme peripheral blood eosinophilia and increased IgE as well as filaria-specific IgG, IgM, and IgE localization in the lungs.4 Histologic examination shows massive pulmonary infiltrations by eosinophils6,33 that are degranulated.6 Furthermore, a recent study reported markedly increased levels of EDN, one of the eosinophil granule basic proteins, both systemically and in the lungs of individuals with TPE.7 Therefore, the results of our study are important because we have investigated the roles of the EDN and ECP genes as part of continuing efforts to clarify the mechanism for development of TPE.
Although we did not observe a relationship between EDN and ECP polymorphisms and TPE development, we did identify two new haplotypes (10 and 11) of EDN. Of interest, haplotype 10 had been predicted as haplotype X in a previous study19 and was directly demonstrated in our analysis.
The present study clearly shows differences in the distribution of polymorphic sites in this south Indian population compared with other populations (Table 1
).19,20 Recent studies have shown an ECP 434 (G/C) polymorphism in Swedish students that was associated with development of allergic symptoms20 and other polymorphisms (393C/T, 38C/A, and 124Arg/Thr) in Japanese children21; however, among the 181 individuals from south India, none of these polymorphisms were seen.
Although TPE is distinguished from other allergic conditions by its elevated antifilarial antibodies and response treatment with antifilarial chemotherapy, there are many similarities in the clinical presentation of TPE and those conditions associated with increased eosinophilia and lung involvement (such as asthma, Churg-Strauss syndrome, the idiopathic hypereosinophilic syndrome, and chronic eosinophilic pneumonia). Although the genetic bases of these other syndromes have not been definitively identified, an association has been demonstrated between an IL-13 variant and atopic dermatitis in three different populations.3436 In addition, there have been many studies linking asthma with multiple different genetic polymorphisms,3739 suggesting that there may well be a molecular but complex (genetic) basis for many of these conditions with lung involvement.
To search for the underlying mechanism in TPE, it is also necessary to consider the filarial worms themselves as an antigen source and host immune responses as a result of exposure to these antigens. Recently,
-glutamyl transpeptidase (
-GT), a major allergen of the lymphatic filarial parasite Brugia malayi, has been implicated in the pathogenesis of TPE.40,41 Molecular mimicry between the parasite
-GT homolog and the host membrane-bound
-GT in lung epithelial cells was has been suggested to contribute to the pathogenesis observed in TPE. In a mouse model, Brugia malayi
-GT induced pulmonary inflammation following intranasal challenge, a reaction believed to reflect a breakdown of tolerance against endogenous murine
-GT in the pulmonary epithelium. However, because such autoimmune reactions against pulmonary epithelium
-GT are not universally found in patients with TPE, other factors important in TPE pathogenesis await elucidation.
Compartmentalization of the inflammatory and immune responses in the lungs of patients with TPE suggest that lung epithelial cells and alveolar macrophages are also important effectors in the pathogenesis of TPE. Among the observations on tissue-dependent immune responses in TPE, a direct interaction has been shown between lung epithelial cells and filarial antigenic components, leading to CD-14-dependent activation of NF-
B42,43 and production of proinflammatory cytokines.44
There have also been many studies examining the relationship between non-Indian populations and those in India regarding genetic origin, genetic flow, and genetic influences, focused usually on population migration.3739,45,46 There is some evidence that in the south Indian population there is an absence of the HIV-1 protective
32 to make
ccr5 allele as well as a region of chromosome 20 associated with leprosy susceptibility.4749 Our study results also showed the different distribution of EDN and ECP in this population compared with other groups, although we failed to show significant association with the development of TPE.
In conclusion, as part of continuing efforts to elucidate the mechanism of TPE, we screened the EDN and ECP polymorphisms in a south Indian population. The EDN and ECP polymorphisms are not likely involved in development of TPE. We continue to examine which groups of individuals with what genetic predispositions develop not only a system and skewed immune response, but also a localized and skewed pulmonary inflammatory response when exposed to certain filarial antigens or live parasites.
Received December 6, 2004.
Accepted for publication December 28, 2004.
Acknowledgment: We thank Brenda Rae Marshall for editorial assistance
* Address correspondence to Yae-Jean Kim, Helminth Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Disease, National Institutes of Health, 4 Center Drive, Building 1, Room B1-07, Bethesda, MD 20892. E-mail: yjkim{at}niaid.nih.gov 
Authors addresses: Yae-Jean Kim and Thomas B. Nutman, Helminth Immunology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Disease, National Institutes of Health, 4 Center Drive, Building 1, Room B1-07, Bethesda, MD 20892, E-mail: tnutman{at}niaid.nih.gov. V. Kumarswami, Tuberculosis Research Centre, Chennai, India. Eunhwa Choi, Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea. Jianbing Mu, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, NIAID, Bethesda, MD 20892. Dean A. Follmann, Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892. Peter Zimmerman, Center for Global Health and Diseases, Case Western Reserve University, University Hospitals of Cleveland, School of Medicine, Cleveland, OH 44106.
 |
REFERENCES
|
- Rao CK, Ramaprasad K, Narasimham MV, Jaggi OP, 1981. Epidemiology of bancroftian filariasis in East Godavari district (Andhra Pradesh)incidence of tropical pulmonary eosinophilia. Indian J Med Res 74: 517523.[ISI][Medline]
- Choi EH, Zimmerman PA, Foster CB, Zhu S, Kumaraswami V, Nutman TB, Chanock SJ, 2001. Genetic polymorphisms in molecules of innate immunity and susceptibility to infection with Wuchereria bancrofti in South India. Genes Immun 2: 248253.[ISI][Medline]
- Ottesen EA, Neva FA, Paranjape RS, Tripathy SP, Thiruvengadam KV, Beaven MA, 1979. Specific allergic sensitisation to filarial antigens in tropical eosinophilia syndrome. Lancet 1: 11581161.[ISI][Medline]
- Nutman TB, Vijayan VK, Pinkston P, Kumaraswami V, Steel C, Crystal RG, Ottesen EA, 1989. Tropical pulmonary eosinophilia: analysis of antifilarial antibody localized to the lung. J Infect Dis 160: 10421050.[ISI][Medline]
- Mahanty S, King CL, Kumaraswami V, Regunathan J, Maya A, Jayaraman K, Abrams JS, Ottesen EA, Nutman TB, 1993. IL-4- and IL-5-secreting lymphocyte populations are preferentially stimulated by parasite-derived antigens in human tissue invasive nematode infections. J Immunol 151: 37043711.[Abstract]
- Pinkston P, Vijayan VK, Nutman TB, Rom WN, ODonnell KM, Cornelius MJ, Kumaraswami V, Ferrans VJ, Takemura T, Yenokida G, Thiruvengadam KV, Tripathy SP, Ottesen EA, Crystal RG, 1987. Acute tropical pulmonary eosinophilia. Characterization of the lower respiratory tract inflammation and its response to therapy. J Clin Invest 80: 216225.
- OBryan L, Pinkston P, Kumaraswami V, Vijayan V, Yenokida G, Rosenberg HF, Crystal G, Ottesen EA, Nutman TB, 2003. Localized eosinophil degranulation mediates disease in tropical pulmonary eosinophilia. Infect Immun 71: 13371342.[Abstract/Free Full Text]
- Hamann KJ, Ten RM, Loegering DA, Jenkins RB, Heise MT, Schad CR, Pease LR, Gleich GJ, Barker RL, 1990. Structure and chromosome localization of the human eosinophil-derived neurotoxin and eosinophil cationic protein genes: evidence for intronless coding sequences in the ribonuclease gene superfamily. Genomics 7: 535546.[ISI][Medline]
- Ackerman SJ, Loegering DA, Venge P, Oslsson I, Harley JB, Fauci AS, Gleich GJ, 1983. Distinctive cationic proteins of the human eosinophil granule: major basic protein, eosinophil cationic protein, and eosinophil-derived neurotoxin. J Immunol 131: 29772982.[Abstract]
- Rosenberg HF, Domachowske JB, 1999. Eosinophils, ribonucleases and host defense: solving the puzzle. Immunol Res 20: 261274.[ISI][Medline]
- Gleich GJ, Loegering DA, Bell MP, Checkel JL, Ackerman SJ, McKean DJ, 1986. Biochemical and functional similarities between human eosinophil-derived neurotoxin and eosinophil cationic protein: homology with ribonuclease. Proc Natl Acad Sci USA 83: 31463150.[Abstract/Free Full Text]
- Domachowske JB, Dyer KD, Bonville CA, Rosenberg HF, 1998. Recombinant human eosinophil-derived neurotoxin/RNase 2 functions as an effective antiviral agent against respiratory syncytial virus. J Infect Dis 177: 14581464.[ISI][Medline]
- Lee-Huang S, Huang PL, Sun Y, Kung HF, Blithe DL, Chen HC, 1999. Lysozyme and RNases as anti-HIV components in beta-core preparations of human chorionic gonadotropin. Proc Natl Acad Sci USA 96: 26782681.[Abstract/Free Full Text]
- Young JD, Peterson CG, Venge P, Cohn ZA, 1986. Mechanism of membrane damage mediated by human eosinophil cationic protein. Nature 321: 613616.[Medline]
- Waters LS, Taverne J, Tai PC, Spry CJ, Targett GA, Playfair JH, 1987. Killing of Plasmodium falciparum by eosinophil secretory products. Infect Immun 55: 877881.[Abstract/Free Full Text]
- Lehrer RI, Szklarek D, Barton A, Ganz T, Hamann KJ, Gleich GJ, 1989. Antibacterial properties of eosinophil major basic protein and eosinophil cationic protein. J Immunol 142: 44284434.[Abstract]
- Hamann KJ, Gleich GJ, Checkel JL, Loegering DA, McCall JW, Barker RL, 1990. In vitro killing of microfilariae of Brugia pahangi and Brugia malayi by eosinophil granule proteins. J Immunol 144: 31663173.[Abstract]
- Venge P, Bystrom J, 1998. Eosinophil cationic protein (ECP). Int J Biochem Cell Biol 30: 433437.[ISI][Medline]
- Zhang J, Rosenberg HF, 2000. Sequence variation at two eosinophil-associated ribonuclease loci in humans. Genetics 156: 19491958.[Abstract/Free Full Text]
- Jonsson UB, Bystrom J, Stalenheim G, Venge P, 2002. Polymorphism of the eosinophil cationic protein-gene is related to the expression of allergic symptoms. Clin Exp Allergy 32: 10921095.[ISI][Medline]
- Noguchi E, Iwama A, Takeda K, Takeda T, Kamioka M, Ichikawa K, Akiba T, Arinami T, Shibasaki M, 2003. The promoter polymorphism in the eosinophil cationic protein gene and its influence on the serum eosinophil cationic protein level. Am J Respir Crit Care Med 167: 180184.[Abstract/Free Full Text]
- Moore D, 1998. Preparation and analysis of DNA. Current Protocols in Human Genetics. New York: John Wiley & Sons, Inc., 2.1.12.1.3.
- Stephens M, Smith NJ, Donnelly P, 2001. A new statistical method for haplotype reconstruction from population data. Am J Hum Genet 68: 978989.[ISI][Medline]
- Sham PC, Curtis D, 1995. Monte Carlo tests for associations between disease and alleles at highly polymorphic loci. Ann Hum Genet 59: 97105.[ISI][Medline]
- Cooray JH, Ismail MM, 1999. Re-examination of the diagnostic criteria of tropical pulmonary eosinophilia. Respir Med 93: 655659.[ISI][Medline]
- Beg MA, Naqvi A, Zaman V, Hussain R, 2001. Tropical pulmonary eosinophilia and filariasis in Pakistan. Southeast Asian J Trop Med Public Health 32: 7375.[Medline]
- Coutinho A, 1956. Tropical eosinophilia: clinical, therapeutic and etiologic considerations. Experimental work. Ann Intern Med 44: 88104.
- Hise AG, Hazlett FE, Bockarie MJ, Zimmerman PA, Tisch DJ, Kazura JW, 2003. Polymorphisms of innate immunity genes and susceptibility to lymphatic filariasis. Genes Immun 4: 524527.[ISI][Medline]
- Meyer CG, Gallin M, Erttmann KD, Brattig N, Schnittger L, Gelhaus A, Tannich E, Begovich AB, Erlich HA, Horstmann RD, 1994. HLA-D alleles associated with generalized disease, localized disease, and putative immunity in Onchocerca volvulus infection. Proc Natl Acad Sci USA 91: 75157519.[Abstract/Free Full Text]
- Meyer CG, Schnittger L, May J, 1996. Met-11 of HLA class II DP
1 first domain associated with onchocerciasis. Exp Clin Immunogenet 13: 1219.[ISI][Medline]
- Murdoch ME, Payton A, Abiose A, Thomson W, Panicker VK, Dyer PA, Jones BR, Maizels RM, Ollier WE, 1997. HLA-DQ alleles associate with cutaneous features of onchocerciasis. The Kaduna-London-Manchester Collaboration for Research on Onchocerciasis. Hum Immunol 55: 4652.[ISI][Medline]
- Hoerauf A, Kruse S, Brattig NW, Heinzmann A, Mueller-Myhsok B, Deichmann KA, 2002. The variant Arg110Gln of human IL-13 is associated with an immunologically hyper-reactive form of onchocerciasis (Sowda). Microbes Infect 4: 3742.[ISI][Medline]
- Udwadia FE, 1967. Tropical eosinophilia. A correlation of clinical, histopathologic and lung function studies. Dis Chest 52: 531538.
- Liu X, Nickel R, Beyer K, Wahn U, Ehrlich E, Freidhoff LR, Bjorksten B, Beaty TH, Huang SK, 2000. An IL-13 coding region variant is associated with a high total serum IgE level and atopic dermatitis in the German multicenter atopy study (MAS-90). J Allergy Clin Immunol 106: 167170.[ISI][Medline]
- Graves PE, Kabesch M, Halonen M, Holberg CJ, Baldini M, Fritzsch C, Weiland SK, Erickson RP, von Mutius E, Martinez FD, 2000. A cluster of seven tightly linked polymorphisms in the IL-13 gene is associated with total serum IgE levels in three populations of white children. J Allergy Clin Immunol 105: 506513.[ISI][Medline]
- Heinzmann A, Mao XQ, Akaiwa M, Kreomer RT, Gao PS, Ohshima K, Umeshita R, Abe Y, Braun S, Yamashita T, Roberts MH, Sugimoto R, Arima K, Arinobu Y, Yu B, Kruse S, Enomoto T, Dake Y, Kawai M, Shimazu S, Sasaki S, Adra CN, Kitaichi M, Inoue H, Yamauchi K, Tomichi N, Kurimoto G, Hamasaki N, Hopkin JM, Izuhara K, Shirakawa T, Dichmann KA, 2000. Genetic variants of IL-13 signalling and human asthma and atopy. Hum Mol Genet 9: 549559.[Abstract/Free Full Text]
- Lin YC, Lu CC, Su HJ, Shen CY, Lei HY, Guo YL, 2002. The association between tumor necrosis factor, HLA-DR alleles, and IgE-mediated asthma in Taiwanese adolescents. Allergy 57: 831834.[ISI][Medline]
- Risma KA, Wang N, Andrews RP, Cunningham CM, Ericksen MB, Bernstein JA, Chakraborty R, Hershey GK, 2002. V75R576 IL-4 receptor á is associated with allergic asthma and enhanced IL-4 receptor function. J Immunol 169: 16041610.[Abstract/Free Full Text]
- van Eerdewegh P, Little RD, Dupuis J, del Mastro RG, Galls K, Simon J, Torrey D, Pandit S, McKenney J, Braunschweiger K, Walsh A, Liu Z, Hayward B, Folz C, Manning SP, Bawa A, Saracino L, Thackston M, Benchekroun Y, Capparell N, Wang M, Adair R, Feng Y, Dubois J, FitzGerald MG, Huang H, Gibson R, Allen KM, Pedan A, Danzig MR, Umland SP, Egan RW, Cuss FM, Rorke S, Clough JB, Holloway JW, Holgate ST, Keith TP, 2002. Association of the ADAM33 gene with asthma and bronchial hyperresponsiveness. Nature 418: 426430.[Medline]
- Lobos E, Zahn R, Weiss N, Nutman TB, 1996. A major allergen of lymphatic filarial nematodes is a parasite homolog of the
-glutamyl transpeptidase. Mol Med 2: 712724.[ISI][Medline]
- Gounni AS, Spanel-Borowski K, Palacios M, Heusser C, Moncada S, Lobos E, 2001. Pulmonary inflammation induced by a recombinant Brugia malayi
-glutamyl transpeptidase homolog: involvement of humoral autoimmune responses. Mol Med 7: 344354.[ISI][Medline]
- Pugin J, Heumann ID, Tomasz A, Kraychenko VV, Akamatsu Y, Nishijima M, Glauser MP, Tobias PS, Ulevitch RJ, 1994. CD14 is a pattern recognition receptor. Immunity 1: 509516.[ISI][Medline]
- Raetz CR, Ulevitch RJ, Wright SD, Sibley CH, Ding A, Nathan CF, 1991. Gram-negative endotoxin: an extraordinary lipid with profound effects on eukaryotic signal transduction. FASEB J 5: 26522660.[Abstract]
- Narayanan K, Seufzer BJ, Brockman-Schneider RA, Gern JE, Balakrishnan A, Miyamoto S, 2002. CD14-dependent activation of NF-
B by filarial parasitic sheath proteins. Cell Biol Int 26: 4354.[ISI][Medline]
- Kivisild T, Rootsi S, Metspalu M, Sdysms D, Kaldma K, Parik J, Metspaul E, Adojaan M, Tolk HV, Stepanov V, Golge M, Usanga E, Papiha SS, Cinnioglu C, King R, Cavalli-Sforza L, Underhill PA, Villems R, 2003. The genetic heritage of the earliest settlers persists both in Indian tribal and caste populations. Am J Hum Genet 72: 313332.[ISI][Medline]
- Bamshad M, Kivisild T, Watkins WS, Dixon ME, Ricker CE, Rao BB, Naidu JM, Prasad BV, Reddy PG, Rasanayagam A, Papiha SS, Villems R, Redd AJ, Hammer MF, Nguyen SV, Carroll ML, Batzer MA, Jorde LB, 2001. Genetic evidence on the origins of Indian caste populations. Genome Res 11: 9941004.[Abstract/Free Full Text]
- Majumder PP, Dey B, 2001. Absence of the HIV-1 protective
ccr5 allele in most ethnic populations of India. Eur J Hum Genet 9: 794796.[ISI][Medline]
- Tosh K, Meisner S, Siddiqui MR, Balakrishnan K, Ghei S, Golding M, Sengupta U, Pitchappan RM, Hill AV, 2002. A region of chromosome 20 is linked to leprosy susceptibility in a South Indian population. J Infect Dis 186: 11901193.[ISI][Medline]
- Zimmerman PA, Buckler-White A, Alkhatib G, Spalding T, Kubofcik J, Combadiere C, Weissman D, Cohen O, Rubbert A, Lam G, Vaccarezza M, Kennedy PE, Kumaraswami V, Giorgi JV, Detels R, Hunter J, Chopek M, Berger EA, Fauci AS, Nutman TB, Murphy PM, 1997. Inherited resistance to HIV-1 conferred by an inactivating mutation in CC chemokine receptor 5: studies in populations with contrasting clinical phenotypes, defined racial background, and quantified risk. Mol Med 3: 2336.[ISI][Medline]